1. Field of the Invention
The present invention relates to a chassis, and more particularly to a chassis for an electric vehicle.
2. Description of the Prior Art
Vehicle is an indispensible part of our lives, and every vehicle has a chassis on which the rest parts of the vehicle are mounted, in other words, the chassis has to bear the load of the vehicle. Therefore, the strength of a chassis has a great influence on the vehicle's safety.
As shown in FIG. 1, a conventional vehicle chassis X comprises a plurality of tubes X1 connected together, and the angles between connected tubes X1 are either right angles or acute angles. The strength of the chassis determines the safety of a vehicle, and the structural weak points lie at the connection point between the tubes X1. When the angles are all right and acute angles, stress concentration will occur, which will cause structural damage and safety problem when the chassis X is overloaded or subjected to an impact force.
FIG. 2 shows another conventional vehicle chassis which includes a base frame Y and an upper frame Z, and the base frame Y, as shown in FIG. 3, includes two opposite middle beams Y1 with two ends slantingly connected to one ends of two first extending beams Y2, and another ends of the first extending beams Y2 are connected to two second extending beams Y3, respectively. The middle beams Y1, the first extending beams Y2 and the second extending beams Y3 are all straight beams without a radius of curvature. The middle beams Y1 are connected to the first extending beams Y2 by two first arc-shaped connectors Y4, and the first extending beams Y2 are connected to the second extending beams Y3 by two second arc-shaped connectors Y5, so that the arc of the arc-shaped connectors avoids a connection point of an acute angle and reduces stress concentration.
However, the base frame Y consists of the middle beams Y1 and the first and second extending beams Y2, Y3, which makes the assembly much difficult. Furthermore, the connection points between the respective beams have stress concentration and are still the weak points of the whole structure.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.